《伤寒论》原文∶少阴病得之二、三日以上，心中烦，不得卧，黄连阿胶汤主之。
二、三日以上，即一日也，合一二三日而浑言之即初得也。细绎其文，是初得即为少阴病，非自他经传
来也。其病既非自他经来，而初得即有热象者，此前所谓伏气化热而窜入少阴者也。盖凡伏气化热之后，恒
因薄受外感而猝然发动，至其窜入之处，又恒因其脏腑素有虚损，伏气即乘虚而入。由斯而论，则此节之所
谓少阴病，乃少阴病中之肾虚兼热者也。夫大易之象，坎上离下为既济，坎为肾而在上者，此言肾当
上济以镇心也，离为心而在下者，此言心当下济以暖肾也。至肾素虚者，其真阴之气不能上
济以镇心，心火原有摇摇欲动之机，是以少阴之病初得，肾气为伏气所阻，欲上升以济心尤难，故他病之现
象犹未呈露，而心中已不胜热象之烦扰而不能安卧矣，是以当治以黄连阿胶汤也。
【黄连阿胶汤】黄连四两，黄芩一两，芍药二两，鸡子黄二枚，阿胶三两。
上五味，以水五升，先煮三味取二升，去滓，纳胶烊尽，小
冷，纳鸡子黄，搅令相得，温取七合，甘三服。
黄连味苦入心，性凉解热，故重用之以解心中发烦，辅以黄芩，恐心中之热扰及于肺也，又肺为肾之
上源，清肺亦所以清肾也。芍药味兼苦酸，其苦也善降，其酸也善收，能收降浮越之阳，使之下归其宅，而
性凉又能滋阴，兼能利便，故善滋补肾阴，更能引肾中外感之热自小便出也。阿胶其性善滋阴，又善潜
伏，能直入肾中以生肾水。鸡子黄中含有副肾髓质之分泌素，推以同气相求之理，更能直入肾中以益肾水，
肾水充足，自能胜热逐邪以上镇心火之妄动，而心中发烦自愈矣。
或问∶提纲明言心中烦而不能卧，夫心与肾共为少阴，使其心之本体热而生烦，其人亦恒不能安卧，此
虽为手少阴，亦可名为少阴病也，何先生独推本于肾，由肾病而累及于心乎？答曰∶凡曰少阴病者，必脉象
微细，开端提纲中已明言之矣。若谓其病发于心，因心本体过热而发烦，则其脉必现浮洪之象，今其心虽
有热，而脉象仍然微细（若脉非微细而有更改者，本节提纲中必言明此定例也），则知其病之源
不在于心而在于肾可知，其心中发烦不得卧，实因肾病而累及于心，更可知也。
此节所言之病，原系少阴病初得无大热者，故治以黄连阿胶汤已足清其热也。若其为日既久，而热
浸加增，或其肾经素有蕴热，因有伏气之热激发之，则其热益甚，以致心肾皆热，其壮热充
实于上下，又非此汤所能胜任矣。愚遇此等证，则恒用白虎加人
参汤，以玄参代知母、山药代粳米，又加鲜茅根，生鸡子黄，莫不随手奏效，用之救人多矣，因名之为
坎离互根汤，详录其方之分量及煎法于下。
生石膏（三两细末） 玄参（一两） 生怀山药（八钱） 甘草（三钱）
野台参（四钱） 鲜白茅根（六两洗净切碎） 生鸡子黄（三枚）
上共六味，先将茅根煎三四沸，去滓，纳余药五味，煎汤三盅，分三次温服，每服一次，调入鸡子黄一枚。
方中之意∶石膏、人参并用，不但能解少阴之实热，并能于邪热炽盛之时立复真阴，辅以茅根更能助肾
气上升与心火相济也。至于玄参，性凉多液，其质轻松，原善清浮游之热，而心之烦躁可除，其色黑入肾，
又能协同鸡子黄以滋肾补阴，俾少阴之气化壮旺，自能逐邪外出也。
或问∶外感之伏气，恒受于冬日，至春日阳升随春日之阳而化热，是以温病多有成于伏气化热者，至伤
寒约皆在于冬日，何亦有伏气化热者乎？答曰∶伏气化热，原有两种化法。伏气冬日受之，伏于三焦脂膜
之中，迟至春日随春日之阳生而化热，此伏气化热之常也。乃有伏气受于冬日，其所伏之处，阻塞腹内升降
之气化，其气化因阻塞而生热，伏气亦可随之化热，此伏气化热之变也。迨其化热之后，或又微受外感而
触发之，其触发之后，又恒因某经素有虚损，乘虚而窜入其经，此所以伤寒病中亦有伏气化热者也。
《伤寒论》原文：少阴病（少阴经受邪所致的病证）发病两三天以上，心中烦躁，无法入睡，用黄连阿胶汤主治。
所谓“两三天以上”，其实指的就是第一天；将一、二、三天合起来笼统地说，就是指刚患病的时候。仔细推敲这段文字，意思是刚患病就是少阴病，而不是从其他经络传变而来的。既然这个病不是从其他经络传来的，而刚患病就有热象，这就是前文所说的伏气（潜伏在体内的病邪）化热并窜入少阴经的缘故。大概凡是伏气化热之后，常常因为轻微感受外感风寒而突然发作，等到它窜入的部位，又往往因为该脏腑素有虚损，伏气就乘虚而入。由此而论，这一节所说的少阴病，属于少阴病中肾虚兼有热邪的类型。
《易经》的卦象中，坎卦（代表水、肾）在上，离卦（代表火、心）在下，称为既济卦。坎为肾而在上，这是说肾应当上行以镇摄心火；离为心而在下，这是说心应当下行以温煦肾水。至于肾素来虚弱的人，其真阴之气不能上行以镇摄心火，心火原本就有动摇欲动的趋势，所以少阴病刚发病时，肾气被伏气阻滞，想要上升以济助心火更加困难，因此其他病症的现象还没有显露，但心中已经承受不住热邪的烦扰而不能安卧了，所以应当用黄连阿胶汤治疗。
【黄连阿胶汤】黄连四两，黄芩一两，芍药二两，鸡子黄（鸡蛋黄）二枚，阿胶三两。
以上五味药，用水五升，先煮前三味药，取药液二升，去掉药渣，加入阿胶使其完全溶化，待药液稍凉后，加入鸡子黄，搅拌均匀，每次温服七合，分三次服用。
黄连味道苦，入心经，性质凉能清热，所以重用它可以解除心中引发的烦躁；辅以黄芩，是担心心中的热邪波及肺脏；另外肺为肾的上源，清肺也就等于清肾。芍药味道兼苦酸，苦味善于降泄，酸味善于收敛，能够收敛降泄浮越的阳气，使其回归本位，且其性凉又能滋阴，兼能通利小便，所以善于滋补肾阴，更能引导肾脏中外感的热邪从小便排出。阿胶性质善于滋阴，又善于潜藏，能直接入肾以滋生肾水。鸡子黄中含有肾上腺髓质的分泌素，根据同气相求的原理，更能直接入肾以补益肾水，肾水充足，自然能战胜热邪、驱逐病邪，从而镇摄妄动的心火，心中的烦躁自然痊愈。
有人问：提纲明确说心中烦躁不能卧，心和肾共同归属于少阴，如果是因为心的本体过热而生烦躁，这个人也常常不能安睡，这虽然属于手少阴心经病，也可以称为少阴病，为什么先生您只推究根源于肾，认为是肾病累及于心呢？回答说：凡是称为少阴病的，脉象一定是微细的，这在开篇提纲中已经明确说明了。如果说病发于心，因为心本体过热而发烦躁，那么脉象一定呈现浮洪之象，现在他心中虽然有热，但脉象仍然微细（如果脉象不是微细而有变化，本节提纲中一定会说明这个定例），就知道病的源头不在心而在肾，可以确定；心中烦躁不能卧，确实是因肾病累及于心，也可以确定了。
这一节所说的病，原本是少阴病初得且没有大热的情况，所以用黄连阿胶汤足以清除热邪。如果病程已久，热邪逐渐加重，或者他的肾经素来蕴积热邪，因伏气的热邪激发，那么热势会更加严重，导致心肾都热，壮热充实于上下，这就不是这个汤剂所能胜任的了。我遇到这类证候，常常使用白虎加人参汤，用玄参代替知母、山药代替粳米，又加入鲜茅根和生鸡子黄，无不随手见效，用它救人很多，因此命名为坎离互根汤，详细记录其方剂分量及煎法如下。
生石膏（三两，研成细末） 玄参（一两） 生怀山药（八钱） 甘草（三钱）
野台参（四钱） 鲜白茅根（六两，洗净切碎） 生鸡子黄（三枚）
以上共六味药，先将茅根煎煮三四沸，去掉药渣，加入其余五味药，煎取药汤三盅，分三次温服，每次服药一次，调入一枚鸡子黄。
方义解析：石膏与人参并用，不仅能解除少阴经的实热，还能在邪热炽盛之时立即恢复真阴；辅以茅根更能帮助肾气上升，与心火相互济助。至于玄参，性质凉润多液，质地轻松，原本善于清除浮游的热邪，从而消除心的烦躁；其色黑入肾，又能协同鸡子黄以滋补肾阴，使得少阴经的气化功能壮旺，自然能驱逐病邪外出。
有人问：外感的伏气，通常在冬天受邪，到了春天随着春季阳气的升发而化为热邪，所以温病多有成于伏气化热的，而伤寒大多发生在冬天，为什么也有伏气化热的情况呢？回答说：伏气化热，原本有两种化生的方法。伏气在冬天受邪，潜伏在三焦脂膜之中，延迟到春天随着春季阳气的生发而化为热邪，这是伏气化热的常理。然而有伏气在冬天受邪，其所潜伏的地方，阻塞了腹内升降的气化功能，气化因阻塞而产生热邪，伏气也可以随之化为热邪，这是伏气化热的变局。等到它化为热邪之后，或许又轻微感受外感而触发它，触发之后，又往往因为某条经络素来虚损，乘虚窜入该经络，这就是伤寒病中也有伏气化热的原因。
Original text from *Shanghan Lun* (Treatise on Cold Pathogenic Diseases): In Shaoyin disease (a syndrome caused by pathogenic invasion of the Shaoyin meridians), occurring two to three days or more after onset, with vexation in the heart and inability to sleep, Huanglian Ejiao Tang (Coptis and Donkey-Hide Gelatin Decoction) is the primary treatment.
"Two to three days or more" actually refers to the first day; speaking collectively of one, two, and three days implies the initial stage of the illness. Careful analysis of the text indicates that it is Shaoyin disease right from the onset, not transmitted from other meridians. Since this disease does not come from other meridians, but presents heat signs immediately upon onset, this is what was previously referred to as latent qi (pathogenic factors lying dormant in the body) transforming into heat and intruding into the Shaoyin meridian. Generally, after latent qi transforms into heat, it often erupts suddenly due to a slight external contraction. When it intrudes into its destination, it frequently takes advantage of pre-existing deficiency in the corresponding zang-fu organs. Therefore, the Shaoyin disease mentioned in this section belongs to the type of Shaoyin disease characterized by kidney deficiency combined with heat.
In the imagery of the *I Ching* (Book of Changes), Kan (representing Water/Kidney) above and Li (representing Fire/Heart) below form the Ji Ji hexagram (After Completion). Kan represents the Kidney located above, indicating that the Kidney should ascend to calm the Heart Fire; Li represents the Heart located below, indicating that the Heart should descend to warm the Kidney Water. In cases where the Kidney is inherently deficient, its True Yin Qi cannot ascend to calm the Heart Fire, leaving the Heart Fire prone to agitation. Thus, at the very beginning of Shaoyin disease, the Kidney Qi is blocked by latent qi, making it even harder for it to ascend and nourish the Heart. Consequently, while other symptoms have not yet manifested, the heart already suffers unbearable vexation from heat, leading to insomnia. Hence, Huanglian Ejiao Tang is indicated.
[Huanglian Ejiao Tang] Huanglian (Coptidis Rhizoma) 4 liang, Huangqin (Scutellariae Radix) 1 liang, Shaoyao (Paeoniae Radix Alba) 2 liang, Jizi Huang (Ovi Galli Albumen) 2 pieces, Ejiao (Colla Corii Asini) 3 liang.
These five ingredients are boiled in 5 sheng of water. First, decoct the first three ingredients to obtain 2 sheng of liquid, then strain out the dregs. Add Ejiao and melt it completely. Once the mixture has cooled slightly, add Jizi Huang, stir well until incorporated, and take 7 ge warm per dose, divided into three doses.
Huanglian is bitter and enters the Heart meridian; its cool nature clears heat. Therefore, it is used in heavy dosage to resolve the vexation arising in the heart. Huangqin is added as an adjunct to prevent heat in the heart from affecting the Lungs. Furthermore, since the Lung is the upper source of the Kidney, clearing the Lung also clears the Kidney. Shaoyao has both bitter and sour flavors; bitterness descends effectively, and sourness astringes effectively. It can restrain and descend floating Yang, guiding it back to its root. Its cool nature nourishes Yin, and it promotes urination. Thus, it nourishes Kidney Yin well and guides exogenous heat from the Kidneys out through urination. Ejiao nourishes Yin and has a property of anchoring/subduing; it enters the Kidney directly to generate Kidney Water. Jizi Huang contains secretions analogous to those of the adrenal medulla. Based on the principle of "like attracts like," it enters the Kidney directly to benefit Kidney Water. When Kidney Water is sufficient, it naturally overcomes heat and expels pathogens, thereby suppressing the reckless movement of Heart Fire, and the heart vexation heals itself.
A question arises: The outline explicitly states "vexation in the heart and inability to sleep." Since Heart and Kidney jointly belong to Shaoyin, if the Heat originates from the Heart's essence causing vexation, the person would also likely be unable to sleep. Although this might be considered Hand-Shaoyin disease, it can still be called Shaoyin disease. Why do you attribute the root cause solely to the Kidney, suggesting Kidney disease affects the Heart? The answer is: Any condition termed Shaoyin disease must present with a faint and thin pulse (Wei-Xi Mai), as clearly stated in the opening outline. If the disease originated in the Heart due to excessive internal heat causing vexation, the pulse would necessarily appear floating and surging (Fu-Hong Mai). However, although there is heat in the heart, the pulse remains faint and thin. (If the pulse were not faint and thin but changed, this fixed rule would be specified in the outline.) Therefore, it is known that the source of the disease lies not in the Heart but in the Kidney. It is further evident that the heart vexation and insomnia are indeed caused by Kidney disease affecting the Heart.
The disease described in this section originally involves early-stage Shaoyin disease without significant heat, so Huanglian Ejiao Tang is sufficient to clear the heat. However, if the duration is long and heat gradually increases, or if the Kidney meridian harbors latent heat exacerbated by latent qi, the heat becomes severe, resulting in heat in both Heart and Kidney. With robust heat filling the upper and lower parts, this decoction is no longer adequate. In such cases, I frequently use Baihu Jia Renshen Tang (White Tiger Plus Ginseng Decoction), substituting Xuanshen (Scrophulariae Radix) for Zhimu (Anemarrhenae Rhizoma), Shanyao (Dioscoreae Rhizoma) for Jingmi (Oryzae Fructus Germinatus), and adding fresh Maogen (Imperatae Rhizoma) and raw Jizi Huang. This formula yields immediate results and has saved many lives; thus, I named it Kanli Hugen Tang (Kan-Li Mutual Root Decoction). The detailed dosage and preparation method are recorded below.
Sheng Shigao (Gypsum Fibrosum) 3 liang (finely powdered), Xuanshen 1 liang, Sheng Huai Shanyao 8 qian, Gancao (Glycyrrhizae Radix et Rhizoma) 3 qian, Yetairen (Panax Ginseng Radix et Rhizoma) 4 qian, Xian Baimaogen (Imperatae Rhizoma) 6 liang (washed and chopped), Sheng Jizi Huang 3 pieces.
These six ingredients are processed together. First, boil the Maogen for three to four boils, strain out the dregs, and add the remaining five ingredients. Decoct to obtain three zhong of liquid. Take warm, divided into three doses. For each dose, mix in one Jizi Huang.
Rationale of the formula: The combination of Shigao and Renshen not only clears excess heat in the Shaoyin meridian but also rapidly restores True Yin during intense pathogenic heat. Maogen assists Kidney Qi in ascending to interact harmoniously with Heart Fire. Xuanshen is cool, moist, and light; it clears floating heat, thereby removing heart vexation. Its black color enters the Kidney, working synergistically with Jizi Huang to nourish Kidney Yin. This strengthens the Qi transformation of Shaoyin, enabling the expulsion of pathogens.
A question arises: Exogenous latent qi is usually contracted in winter and transforms into heat in spring following the rising Yang of spring; thus, warm diseases often result from latent qi transforming into heat. Since cold damage (Shanghan) mostly occurs in winter, why is there also latent qi transforming into heat? The answer is: There are two modes of latent qi transforming into heat. Latent qi contracted in winter lies dormant in the membranes of the Sanjiao (Triple Burner) and transforms into heat in spring with the rising Yang; this is the normal mode. However, latent qi contracted in winter may lodge in places that obstruct the ascending and descending Qi transformation in the abdomen. This obstruction generates heat, causing the latent qi to transform into heat as well; this is the variant mode. After transforming into heat, if triggered by a slight external contraction, and given that certain meridians may have pre-existing deficiencies, the pathogen intrudes into these meridians. This explains why latent qi transforming into heat also occurs in Shanghan diseases.